Regarding techniques for discharging a liquid material, such as an adhesive, onto a substrate, there is known, as the screw type, a method of rotating a screw, for example, which includes a spiral blade formed on a surface of a rod-like member extending in an axial direction, and of feeding the liquid material by the blade with rotation of the screw to be discharged. Such a method is widely used in particular to discharge a high-viscous liquid material and a liquid material containing filler.
With respect to a screw type discharge apparatus, Patent Reference 1, for example, discloses a viscous material application apparatus including a syringe that stores a viscous material; a pressurizing device that pressurizes an inner space of the syringe; a viscous material application member that receives and guides the viscous material pneumatically fed under pressurization; a viscous material supply tube that connects the syringe and the viscous material application member to each other, and that allows the viscous material to pass therethrough for supply of the viscous material to the viscous material application member from the syringe; a discharge shaft that is a rod-like member fitted into a hollow portion extending through the viscous material application member in a lengthwise direction, and that includes, at its one end, a screw portion for feeding the viscous material, which is guided by the viscous material application member, in an axial direction under pressurization with rotation of the discharge shaft about an axis thereof; a nozzle that discharges the viscous material, which is fed under pressurization with the rotation of the discharge shaft, to the outside; a rotation mechanism that rotates the nozzle about a nozzle axis; an application target holder that holds an application target in a restricted state; and a controller, the viscous material discharge apparatus being operated, under control by the controller, in a manner of moving one or both of the nozzle and application target holder for relative positioning, and of moving the nozzle downward to apply a fixed amount of the viscous material discharged from the nozzle to a predetermined position on the application target, wherein the viscous material supply tube is joined to the viscous material application member in a state rotatable together with the viscous material application member.
Furthermore, Patent Reference 2 discloses a creamy solder application apparatus wherein a motor having a rotation shaft provided with a first connecting member at an end thereof is mounted to a base with the first connecting member positioned on the lower side, a pump unit is constituted by a screw provided with a second connecting member of which one end engaged with the first connecting member, and by a cylinder that accommodates the screw, and that has a creamy solder inlet formed in a lateral portion through which a creamy solder flows into the cylinder from the outside, an insertion hole is formed in the base as a through-hole being coaxially with the rotation axis and having a diameter enough to accommodate the cylinder, and the cylinder is accommodated in the insertion hole in a state not rotatable, but movable in the axial direction.
Moreover, Patent Reference 3 discloses a paste discharge apparatus comprising a main body that includes a liquid chamber opened at an upper end and having a circular sectional shape, and a nozzle that ejects a paste in the liquid chamber, a syringe that stores the paste supplied to the liquid chamber, and a gas supply unit that supplies pressurized gas into the syringe, wherein the main body is constituted such that a screw for feeding the paste to the nozzle when driven to rotate is detachably mounted into the liquid chamber, and that a lid member for closing an opening of the liquid chamber is detachably attached in a state where the screw is demounted.
In addition, the applicant has proposed a liquid material discharge apparatus comprising a liquid contact unit including a nozzle, a storage container, and a discharge member, which are integrally constituted with the aid of a housing, and a main body unit including a holder provided with a support member to which the housing is attached, and a drive unit that operates the discharge member, the liquid contact unit and the main body unit being attachable and detachable by constituting the discharge member and the drive unit to be attachable and detachable with a coupling member and by constituting the housing and the holder to be attachable and detachable, wherein the housing is horizontally movable in a state supported by the support member to be attached to and detached from the holder, and the discharge member and the drive unit are attachable and detachable with vertical movement of the housing while the housing is held in the state attached to the holder (Patent Reference 4).